Device for gripping elongated members

ABSTRACT

Device used for withdrawing from a well a section of drill string wedged therein. The device includes a rod ending with a prolonging member containing a sock-like member adapted to cap said drill string section and to contract under the effect of a longitudinal traction force applied thereto while raising said rod, thereby gripping the drill string section as a result of the friction force generated by said contraction.

United States Patent Chatard et al.

[54] DEVICE FOR GRIPPING ELONGATED MEMBERS [72] Inventors: MichelChatard, Chatou; Pierre Grolet, Montesson; Remi Reynarcl, Viroflay, allof France [73] Assignee: Institut Francais Du Petrole Des Carburants EtLubrifiants, Rueil I58] Field of Search 294/86, 86 CG, 86.1, 86.14,294/86.15, 86.26, 86.32; 174/84 [56] References Cited UNITED STATESPATENTS r,

1,521,789 l/l925 Oswald ..294/86.26

21 l 91 I 01 I 01 I 0| 51 Oct. 10, 1972 2,434,358 l/ 1948 Frank ..l74/84Primary Examiner-Even C. Blunk Assistant Examiner-Johnny D. CherryAttorney-Craig, Antonelli & Hill [57] ABSTRACT Device used forwithdrawing from a well a section of drill string wedged therein. Thedevice includes a rod ending with a prolonging member containing asocklike member adapted to cap said drill string section and to contractunder the effect of a longitudinal traction force applied thereto whileraising said rod, thereby gripping the drill string section as a resultof the friction force generated by said contraction.

l 1 Claims, 6 Drawing Figures mini sum 1 or 3 FIG.1A

f 00 t Ma PATENTEDncI 10 I972 wax SHEET 2 [IF 3 1114 1 DEVICE FORGRIPPING ELONGATED MEMBERS This invention relates to a device forgripping an elongated member, particularly useful for withdrawing saidmember from a location where it is difficult to access.

In the following there will be referred, by way of non limitativeexample, to the fishing of a portion of drill string, e.g., formed ofrigid drill stems used in rotary drilling, or a section of flexible pipewhen drilling with a bottom motor suspended therefrom.

During drilling operations it may happen that a breakage of the drillstring occurs. A lower portion of the drill string at the end of whichis secured the drilling tool is thus lost in the well and it ispractically impossible to restart the drilling operation as long as thislower portion of the drill string has not been removed.

It is thus necessary to conduct fishing operations for recovering thelower portion of the drill string. These operations are often difficultto carry out and are the more expensive as they also immobilize thedrilling installation for a long time.

The fishing devices used up to now are very complex and require cuttingoff sections, on the portion of drill string to be recovered. Thisresults in a further increase of the operation time and of its cost.

It is therefore an object of this invention to provide a simple deviceavoiding the above-mentioned disadvantages and which is efficient andeasy to use.

A device according to the invention for gripping an elongated memberwedged in a well, comprises: in combination, an an operating rod havingone end which is adapted to be introduced into the well, a prolongingmember for said rod at said end, said prolonging member being made solidwith said rod and comprising internally a sock-like member or sockformed of a netting of wires, metal cables or strands, the two ends ofsaid sock being respectively secured on said prolonging member and onsaid operating rod, said sock being adapted to cap the elongated member,means for disengaging said prolonging member from said operating rod andmeans for constricting said sock on the elongated member for ensuringthe gripping thereof. The means for disengaging using relative axialdisplacement of the prolonging member and the operating rod for carryingout its function.

The invention will be better understood and further advantages thereofmade apparent from the following description of a non-limitativeembodiment illustrated in the accompanying drawings wherein FIGS. 1 Aand 1 B respectively illustrate the upper and the lower portion of thedevice; and

FIGS. 2 A, 2 B, 3 A and 3 B illustrate the operation of the device.

On FIGS. 1 A and 1 B the device according to the invention is indicatedas a whole by reference 1. This device comprises a member inprolongation of an operating rod 14, formed in this embodiment of a verylong tubular member 2 at the end of which is secured another tubularmember 3 carrying the drilling tool 4 of the crown type. At the upperpart of member 2 and above a shoulder l l is slidably mounted a hollowpiston 5. Piston 5 is made solid with member 2, in the position shown inFIG. 1 A, through fingers 6 in engagement with orifices 7 provided inmember 2.

Channels 10 establish a communication between the central bore of piston5 and an annular space 20 formed between member 2 and piston 5 aboveshoulder l 1.

Fingers 6 are maintained engaged in orifices 7, against the counteraction of springs 8, by means of a sleeve 9 slidable in the bore ofpiston 5. This sleeve 5 is maintained at its uppermost position by aspring 12 which bears respectively on an internal shoulder of the boreof piston 5 and on a shoulder of sleeve 9. In this position the sleeve 9obstructs orifices 10. This sleeve 9 is provided with a port hole 10aand grooves 13 for purposes which will be made apparent hereinafter.

In its uppermost position (FIG. 1 A) the sleeve 9 comes in abutmentagainst the operating rod 14. This rod 14 from which is suspended thedevice 1 is made solid with piston 5, through a threaded connection.

At the lower part of piston 5 is anchored, by any convenient means, asheath or sock-like member 15. This sock-like member is formed of anetting of wires, cables or strands. When this sock is not subjected toany axial tensile stress, it has an external diameter equal to theinternal diameter of tubular member 2. This sock member 15 has aninternal diameter greater than the external diameter of the drill string16 to be withdrawn from the well. This sock-like member 15 is anchoredat its lower part on tubular member 3. The weaving of this sock-likemember is such that a very substantial decrease of its diameter isobtained when it is subjected to axial tensile stresses.

A centering device 17 comprising at its upper part a frusto-conicalelement is maintained in member 3 by means of shear pins 18.

When after breaking of the drill string it is desired to recover thelower part 16 thereof remaining in the well 19, the operation is asfollows.

The device 1 is introduced, while driven in rotation through the rod 14,into the well 19. The tool 4 bores a hole of the well enabling thedevice 1 to cap the drill string 16. During this stage of the processthe drilling fluid circulates through the central duct of pipe 14, asindicated by the arrows in FIGS. 1 A and 1 B. This fluid irrigates thedrilling tool 4, thus making easier its boring action.

In the case where the drill string 16 is a flexible pipe formed of atubular core coated with a plurality of metal armourings, the guidingmember 17 makes it possible to compress, at the level of the breaking,the armourings which might deviate from the drill string axis whileprotecting the sock-like member 15 against any deterioration.

When device 1 is in the position shown in FIGS. 1 A and 1 B a ball 22 isintroduced into the bore of pipe 14. As it is apparent in FIG. 2 A, thisball comes to abutment on a seat arranged therefor in the hole of sleeve9 and interrupts any circulation of drilling fluid.

An increase of the drilling fluid pressure then produces a lowering ofsleeve 9 in the hole of piston 5 (FIG. 2 A) against the counter actionof elastic return means such as spring 12. This movement is continueduntil the recess 13 registers with fingers 6. In this position, shown inFIG. 2 A, the fingers 6 which maintained the piston 5 solid with thetubular member 2 are disengaged from the latter by the action ofrepelling means such as the return springs 8 and by engagement intorecess 13 make piston 5 solid with sleeve 9. The port holes or conduitsa then register with conduits 10 thus establishing communication betweenthe hole of sleeve 9 and the annular space 20. The drilling fluid thanflows to said annular space 20 through port holes 10a and conduits 10 asshown by the arrow in FIG. 2 A.

The tubular member 2 and the piston 5 being no longer solid with eachother as already stated, the drilling fluid pressure produces a loweringof member 2 with respect to piston 5. This movement, favored by the ownweight of member 2, results in the shearing of the shear pins 18 on theone hand andin the lengthening of the sock-like member surrounding thedrill string 16, on the other hand.

As shown in FIGS. 3 A and 3 B, the lengthening of the sock-like member15 results in a very strong constriction being favored by thecirculation of drilling fluid in the direction shown by the arrows inFIGS. 3 A and 3 B.

After the sock-like member has been placed and gripped onto the drillstring 16 the latter is withdrawn by raising the rod 14, which issolidly threaded with piston 5, thereby increasing the tensile stressexerted on the sock-like member and increasing the constriction thereofonto the drill string 16.

The wires, cables or strands of the sock like member may be selected ofa sufficient hardness so that under the effect of the tensile stressthey become sealed in the external wall of the drill string 16. Thesock-like member length in contact with the drill string 16 must besufficient (in most cases in excess of approximately 10 yards) forresulting in a total friction force of the cable strands of the socklikemember on the drill string to compensate the weight of the portionthereof which has to be withdrawn from the well.

What we claim is:

l. A device for the withdrawal of an elongated member wedged in a wellcomprising the combination of an operating rod, one end of which isdestined to be introduced into the well, a prolonging member for saidrod at said end thereof, said prolonging member being made solid withsaid rod, a sock-like member formed of a netting of metal wires, cablesor strands, placed inside said prolonging member, the two ends of saidsock-like member being respectively secured to said prolonging memberand to said operating rod, said sock-like member being adapted to capthe elongated member, means for disengaging said prolonging member fromsaid operating rod, and means for constriction of said sock-like memberon said elongated member, insuring the gripping of the elongated memberby axial displacement of the prolonging member with respect to theoperating rod.

2. A device according to claim 1 wherein said operating rod and saidprolonging member are provided with at least one device for making themsolid with each other and formed with two latching elements respectivelycarried on said rod and said prolonging member, said latching elementsconsisting of at least one retractable finger and at least one clampingorifice for this finger and a slidable sleeve provided with a recess forthe disengagement of said retractable finger, elastic means maintainingsaid sleeve to a position where it locks said retractable finger in aposition of engagement with said clamping orifice against the counteraction of a repelling device which tends to urge said finger back to aposition of disengagement, said means for disengaging being adapted tomake said sleeve slide up to a position of disengagement at which thedisengagement recess registers with the retractable finger, so that thelatter can be disengaged from its clamping orifice by the action of saidrepelling device.

3. A device according to claim 2 with an operating rod comprising anaxial bore for the passage of pressurized fluid, wherein said operatingrod and the slidable sleeve are each provided with at least one conduitregistering with one another in said position of disengagement, therebyestablishing a communication between said bore and an annular spacearranged between said operating rod and said prolonging member and meansadapted to obstruct said sleeve so as to displace the same, by theaction of the fluid pressure against the counter action of elasticmeans, to a position of disengagement at which the flow of fluid in saidannular space insures the axial displacement of the prolonging memberwith respect to said operating rod.

4. An arrangement for withdrawing an elongated member which is wedged ina bore open only at one end, said arrangement comprising: an operatingrod having a lower end adapted to be lowered into said bore, a sock-likemember having an inner diameter which contracts when the sock-likemember is stretched and expands when the sock-like member is compressed,said sock-like member having an upper end fixed with respect to thelower end of the operating rod and a lower end in alignment with saidelongated member when said operating rod is in said bore, said lower endportion of the sock-like member having an inner diameter greater thanthe outer diameter of said elongated member when said sock-like memberis in a relatively unstretched condition, holding means for holding thelower end of said sock-like member a fixed distance from the lower endof said operating rod while the operating rod and sock-like member arebeing lowered over the elongated member, and disengaging means fordisengaging the holding means so as to permit the lower end of saidsock-like member to move with respect to said operating rod so that aportion of said sock-like member can grip the elongated member.

5. An arrangement according to claim 4, characterized in that saidholding means includes means forming a rigid connection between saidoperating rod and the lower end of said sock-like member.

6. An arrangement according to claim 4, characterized in that saidsock-like member is rigidly connected at its lowermost end to a sleevesurrounding the sock-like member and the lower end of said operatingrod, said holding means including means for fixing the position of saidsleeve with respect to the operating rod.

7. An arrangement according to claim 6, characterized in that a pistonis arranged inside of said sleeve with an upper end of said pistonrigidly attached to said operating rod, said holding means includingspring biased pin means connecting said sleeve and piston.

8. An arrangement according to claim 7, characterized in that saidreleasing means includes fluid means operated by fluid flowing throughsaid operating rod.

9. An arrangement according to claim 8, characterized in that saidreleasing means includes a ball selectively positioned in said operatingrod for effecting top of the elongated member to be withdrawn.

1 1. An arrangement according to claim 6, characterized in that saiddisengaging means includes fluid means for forcibly sliding said sleevewith respect to said operating rod whereby positive gripping of theelongated member takes place.

* II l

1. A device for the withdrawal of an elongated member wedged in a wellcomprising the combination of an operating rod, one end of which isdestined to be introduced into the well, a prolonging member for saidrod at said end thereof, said prolonging member being made solid withsaid rod, a sock-like member formed of a netting of metal wires, cablesor strands, placed inside said prolonging member, the two ends of saidsock-like member being respectively secured to said prolonging memberand to said operating rod, said sock-like member being adapted to capthe elongated member, means for disengaging said prolonging member fromsaid operating rod, and means for constriction of said socklike memberon said elongated member, insuring the gripping of the elongated memberby axial displacement of the prolonging member with respect to theoperating rod.
 2. A device according to claim 1 wherein said operatingrod and said prolonging member are provided with at least one device formaking them solid with each other and formed with two latching elementsrespectively carried on said rod and said prolonging member, saidlatching elements consisting of at least one retractable finger and atleast one clamping orifice for this finger and a slidable sleeveprovided with a recess for the disengagement of said retractable finger,elastic means maintaining said sleeve to a position where it locks saidretractable finger in a position of engagement with said clampingorifice against the counter action of a repelling device which tends tourge said finger back to a position of disengagement, said means fordisengaging being adapted to make said sleeve slide up to a position ofdisengagement at which the disengagement recess registers with theretractable finger, so that the latter can be disengaged from itsclamping orifice by the action of said repelling device.
 3. A deviceaccording to claim 2 with an operating rod comprising an axial bore forthe passage of pressurized fluid, wherein said operating rod and theslidable sleeve are each provided with at least one conduit registeringwith one another in said position of disengagement, thereby establishinga communication between said bore and an annular space arranged betweensaid operating rod and said prolonging member and means adapted toobstruct said sleeve so as to displace the same, by the action of thefluid pressure against the counter action of elastic means, to aposition of disengagement at which the flow of fluid in said annularspace insures the axial displacemenT of the prolonging member withrespect to said operating rod.
 4. An arrangement for withdrawing anelongated member which is wedged in a bore open only at one end, saidarrangement comprising: an operating rod having a lower end adapted tobe lowered into said bore, a sock-like member having an inner diameterwhich contracts when the sock-like member is stretched and expands whenthe sock-like member is compressed, said sock-like member having anupper end fixed with respect to the lower end of the operating rod and alower end in alignment with said elongated member when said operatingrod is in said bore, said lower end portion of the sock-like memberhaving an inner diameter greater than the outer diameter of saidelongated member when said sock-like member is in a relativelyunstretched condition, holding means for holding the lower end of saidsock-like member a fixed distance from the lower end of said operatingrod while the operating rod and sock-like member are being lowered overthe elongated member, and disengaging means for disengaging the holdingmeans so as to permit the lower end of said sock-like member to movewith respect to said operating rod so that a portion of said sock-likemember can grip the elongated member.
 5. An arrangement according toclaim 4, characterized in that said holding means includes means forminga rigid connection between said operating rod and the lower end of saidsock-like member.
 6. An arrangement according to claim 4, characterizedin that said sock-like member is rigidly connected at its lowermost endto a sleeve surrounding the sock-like member and the lower end of saidoperating rod, said holding means including means for fixing theposition of said sleeve with respect to the operating rod.
 7. Anarrangement according to claim 6, characterized in that a piston isarranged inside of said sleeve with an upper end of said piston rigidlyattached to said operating rod, said holding means including springbiased pin means connecting said sleeve and piston.
 8. An arrangementaccording to claim 7, characterized in that said releasing meansincludes fluid means operated by fluid flowing through said operatingrod.
 9. An arrangement according to claim 8, characterized in that saidreleasing means includes a ball selectively positioned in said operatingrod for effecting the transfer of fluids to change the relative positionof said piston and said sleeve.
 10. An arrangement according to claim 6,characterized in that said sleeve has an upwardly tapered conical hollowmember for guiding the sleeve over the top of the elongated member to bewithdrawn.
 11. An arrangement according to claim 6, characterized inthat said disengaging means includes fluid means for forcibly slidingsaid sleeve with respect to said operating rod whereby positive grippingof the elongated member takes place.